A package family for the emerging high current converters for PCs

Power dissipation in MOSFETs is largely dominated by its on-resistance, /sub RDS(ON)/ and dynamic losses. The continuous demands by the electronic industry to lower the losses and produce smaller footprints have spurred the semiconductor manufacturers into a flurry of research and development to meet these requirements. Several new packages by all the major players were introduced to address three distinct requirements, namely: a) ultra low parasitic resistance and inductance to minimize losses, b) smaller footprint to increase the power and current densities in new designs, and c) lower thermal resistance and flexibility of heat sinking allowing the switching devices to operate at a much higher power densities than those ever achieved before. We also discuss in some details a new package, BGA from Fairchild Semiconductor that brilliantly addresses these demands; we examined its advantages and we showed that it represents a major departure from the status quo of package design.